Semiconductor devices are widely used today in many electronic applications, such as televisions, children's toys, and computers. Manufacturers of semiconductor devices are working with new materials, new processes, and new technologies daily to develop new semiconductor devices that are a fraction of the size of their ancestors. The smaller the size of the semiconductor device, the smaller the electronic application can be designed. The smaller the size of the electronic application, the more likely consumers are to use the electronics in every day life. This is very evident from the evolution of the computer from the large, slow information processing computers of the 1980's to the fast handheld devices of today.
A typical semiconductor device is manufactured from a number of components including a semiconductor die or “chip” that has been fabricated according to traditional film deposition, masking, etching, and doping processes, a hermetically sealed housing, an absorbing material, such as a getter and/or desiccant material, and strands of wire to connect the die to pins on the housing. Typically, the die is placed in one half of the housing and the strands of wire are connected from the die to the pins on the housing that will provided a means for communicating between the die and the electronic application. Once the die has been seated in the housing, and the strands of wire properly connected, the top half of the housing may be secured to the bottom half of the housing to seal the die within the housing and protect the die from outside contaminants and moisture. While hermetically sealing the die prevents new contaminants from reaching the die, the sealing process does not rid the housing of contaminants that may already be trapped in the housing or contaminants that may be caused by a welding process used to seal the two halves of the housing.
Typically, absorbing material has been added to the device package as a means of absorbing and holding the contaminants and/or moisture present in the housing after the housing has been hermetically sealed. The absorbing material is generally located on the lid of the housing. While the positioning of the absorbing material on the lid of the housing has adequately absorbed contaminants in past devices, new electronic applications are requiring smaller semiconductor devices with the ability to process more information at increasing speeds than the past devices. Further, many semiconductor devices function optically and require a glass window in the top half of the housing to access the die optically. The requirements for smaller device designs require that the glass top half of the housing be recessed to accommodate the desiccant material. This has the effect of either reducing the functional optical die area or increasing the overall package size to regain functionality.
The embodiments described hereinafter were developed in light of this situation and the drawbacks associated with existing systems.